In many board or plywood manufacturing processes, especially those employed for the manufacture of strand board, a raw material must be treated in various stages requiring transportation between and through the stages. In the conventional systems, transportation, washing and filtering of the wood chips, barks and other particles are carried out on a filtering or caul screen which functions to both transport the material through the various processing stages and also to filter liquid material such as a wash liquid which may include conditioning chemicals such as acids through the screen to maintain the desired flow density in the slurry. In addition, the material is subjected to high temperature steam and pressure.
In the past, such screens have been made from woven carbon steel wire formed into a cable from a number of wires where the twists in the thus formed cable have been on the order of 6 to 8 twists per inch. Unfortunately, the increasing throughout speeds of the strand board manufacturing equipment and the nature of the use of such screens both in terms of the collision impacts with the wood chips and bark but also the chemicals and temperatures to which the screens are exposed, has undesirably foreshortened the useful life of such screens. As one result of production costs are increased since the removal, repair and reinstallation of repaired or new screens is a very time consuming and labor intensive process.